We dont what killed our pigeon

Question
We found a beautiful white pigeon in our front yard that had apparently hurt it's wing and been pecked on the back of it's head a bit. We caught it and out it in a medium sized (rabbit-sized) cage for safety. Noticed it had a red band on it's ankle but no numbers. It seemed used to people and pleasant, although a bit puffed up like it was nervous or cold. We kept all sides of the cage covered except for the front, and placed it on a cart on the patio that left for no sides for animals to climb or sit on. It drank water, ate (we bought pigeon feed) and pooped alot. We were very shocked and sad this morning to find it dead inside it's cage this morning. It seems to have been attacked and eaten by something, but we can't figure out by what. The cage door is locked shut. The blanket covering the cage was in tact. It usually stayed at the front of the cage, seemingly to look at or for us. And the was no sign of any animal hair in or around the cage. No animal tracks of any kind. The cages slats/bars are about 1 1/2 inches apart or so. I can't imagine what couldn't have gotten in there, done so much damage, and escaped without a trace. Have you ever heard of such a thing? Any idea what it could have been?

Answer
Sorry!  Your question was very complete, but I have no idea.

Pigeons have many predators, and they are all adept at killing them.  Cats, Raccoons, Opossums, Hawks rank the highest on that list.  Weasels, Owls, Dogs, Children, Skunks, etc also take more than their fair share.

Wish I could help you more, but I have lost birds to all of the above and more and it is usually not obvious who the culprit is.

Dave